. The Bell System technical journal . eaking down shunts the local holding circuit of the crosspoint causingit to release. The — 130-volt disconnect signal is applied during therelease time of the slow release relay which is long enough to insure therelease of the crosspoint relay at the concentrator. The release circuit is individual to the trunk and independent of thesignal sent over the control pairs. g. Pulse Signalling Circuits To control the concentrator four distinct pulse signals are transmittedfrom the central office. Two of these at times must be transmittedsimultaneously, bvit these
. The Bell System technical journal . eaking down shunts the local holding circuit of the crosspoint causingit to release. The — 130-volt disconnect signal is applied during therelease time of the slow release relay which is long enough to insure therelease of the crosspoint relay at the concentrator. The release circuit is individual to the trunk and independent of thesignal sent over the control pairs. g. Pulse Signalling Circuits To control the concentrator four distinct pulse signals are transmittedfrom the central office. Two of these at times must be transmittedsimultaneously, bvit these and the other two are transmitted mutuallyexclusively. In addition, service request and line busy signals are trans-mitted from the concentrator to the central office. The two way trans-mission of information is accomplished on each pair by sending signals ineach direction at different times and inhibiting the receipt of signalswhen others are being transmitted. To transmit four signals over two such pairs, both positive and nega-. CONTROLPAIR NO. 1 VF M LB
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Keywords: ., bookcentury1900, bookdecade1920, booksubjecttechnology, bookyear1
